U.S. patent number 4,859,754 [Application Number 07/260,261] was granted by the patent office on 1989-08-22 for water and oil repellant having desoiling properties.
This patent grant is currently assigned to Asahi Glass Company, Ltd.. Invention is credited to Takashige Maekawa, Kazuya Oharu, Tomoko Sakaguchi.
United States Patent |
4,859,754 |
Maekawa , et al. |
August 22, 1989 |
Water and oil repellant having desoiling properties
Abstract
A water and oil repellant having desoiling properties composed
of a polyfluorinated group-containing copolymer obtained by
copolymerizing the following monomers a and b as essential
constituting components: a: a polyfluorinated group-containing
monomer b: an amphipathic monomer having a hydrophilic moiety and a
lipophilic moiety.
Inventors: |
Maekawa; Takashige (Yokohama,
JP), Oharu; Kazuya (Yokohama, JP),
Sakaguchi; Tomoko (Fukuoka, JP) |
Assignee: |
Asahi Glass Company, Ltd.
(Tokyo, JP)
|
Family
ID: |
17380092 |
Appl.
No.: |
07/260,261 |
Filed: |
October 20, 1988 |
Foreign Application Priority Data
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Oct 20, 1987 [JP] |
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62-262752 |
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Current U.S.
Class: |
526/245;
526/243 |
Current CPC
Class: |
C08F
220/24 (20130101); D06M 15/277 (20130101) |
Current International
Class: |
D06M
15/277 (20060101); D06M 15/21 (20060101); C08F
220/00 (20060101); C08F 220/24 (20060101); C08F
018/20 () |
Field of
Search: |
;526/245,243 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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53-134786 |
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Nov 1978 |
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JP |
|
53-134787 |
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Nov 1978 |
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JP |
|
170801 |
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Jul 1986 |
|
JP |
|
Primary Examiner: Schofer; Joseph L.
Assistant Examiner: Sarofim; N.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier
& Neustadt
Claims
We claim:
1. A water and oil repellant having desoiling properties composed
of a polyfluorinated group-containing copolymer obtained by
copolymerizing the following monomers a and b as essential
constituting components:
a: a polyfluorinated group-containing monomer
b: an amphipathic monomer having a hydrophilic moiety and a
lipophilic moiety.
2. The water and oil repellant according to claim 1, wherein the
weight ratio of a/b in the polyfluorinated group-containing
copolymer. is 65-95/5-35, and the total content of a and b in the
copolymer is at least 80% by weight.
3. The water and oil repellant according to claim 1, wherein the
polyfluorinated group-containing monomer is a monomer containing a
perfluoroalkyl group having from 3 to 20 carbon atoms.
4. The water and oil repellant according to claim 1, wherein the
polyfluorinated group-containing monomer is an acrylate or
methacrylate containing a perfluoroalkyl group having from 3 to 20
carbon atoms.
5. The water and oil repellant according to claim 1, wherein the
amphipathic monomer is a monomer containing mixed polyoxyalkylene
groups constituting the hydrophilic moiety and the lipophilic
moiety.
6. The water and oil repellant according to claim 1, wherein the
amphipathic monomer is an acrylate or methacrylate having the
following formula:
wherein R.sup.1 is H or CH.sub.3, R.sup.2 is H or a C.sub.1
-C.sub.20 alkyl or aralkyl group, m.gtoreq.1, n.gtoreq.1,
n.gtoreq.1, and 60.gtoreq.m+n.gtoreq.2.
Description
The present invention relates to a high performance water and oil
repellant which is capable of providing excellent desoiling
properties, while maintaining high water repellency.
Heretofore, water and oil repellants composed of polymers or
copolymers of a polyfluorinated group-containing monomer such as a
perfluoroalkyl acrylate have been widely known. For example,
Japanese Unexamined Patent Publication Nos. 75472/1974, 20991/1975,
134786/1978 and 134787/1978 and U.S. Pat. Nos. 3,654,244 and
3,920,614 propose water and oil repellants composed of copolymers
obtained by copolymerizing a hydrophilic group-containing monomer
to a polyfluorinated group-containing monomer for the purpose of
imparting desoiling properties whereby deposited stains can readily
be removed e.g. by washing (generally called desoiling or
soil-removing properties or SR properties).
The above-mentioned conventional SR type water and oil repellants
are usually inadequate in the water repellency and at the same time
have the following difficulties with respect to the SR properties.
Namely, a deterioration is observed in the effect for providing
water repellency after the washing treatment, and the desoiling
properties after exposed to a severe condition tend to be
inadequate, thus leading to practical difficulties. For example,
with conventional SR type water and oil repellants, the SR
properties are inadequate against stains adhered during the wearing
for a relatively long period of time, or against stains left
adhered for a long period of time since their deposition until the
washing operation, although they are capable of exhibiting adequate
SR properties against a low level of stains.
In order to solve such a problem, the present applicant has
previously proposed in a patent application a water and oil
repellant composed of a copolymer obtained by copolymerizing a high
Tg methacrylate monomer at a specific copolymerization ratio as a
third component to a polyfluorinated group-containing monomer/a
hydrophilic group-containing monomer. (See Japanese Patent
Application No. 170801/1986.)
From a further research, the present inventors have found the
following problem with the above-mentioned copolymerization system
of a polyfluorinated group-containing monomer/a hydrophilic
group-containing monomer. Namely, with the above-mentioned
copolymerization system, although high performance may be obtained
by solution polymerization, it is difficult to smoothly conduct the
copolymerization reaction of the polyfluorinated group-containing
monomer and the hydrophilic group-containing monomer by
copolymerization in an aqueous dispersion system such as by
emulsion polymerization. Accordingly, it used to be difficult to
attain high levels of water and oil repellency and SR
properties.
It is an object of the present invention to overcome both of the
above-mentioned problems inherent to conventional SR type water and
oil repellants and to provide a SR type water and oil repellant
which is capable of providing adequate SR properties against heavy
stains and which has high water repellency.
As a result of various researches and studies with the above
object, the present inventors have made the following very
interesting discoveries. Namely, it has been found possible to
smoothly and advantageously conduct the copolymerization reaction
not only by solution polymerization but also by polymerization in
an aqueous dispersion system such as by emulsion polymerization, by
employing an amphipathic monomer having not only a hydrophilic
moiety but also a lipophilic moiety in the molecule, as a monomer
to be copolymerized with the polyfluorinated group-containing
monomer. Further, it has been found that by employing such an
amphipathic monomer, excellent SR properties can be obtained while
maintaining the water and oil repellency, and even by the
polymerization in an aqueous dispersion system, it is possible to
obtain both the water and oil repellency and the SR properties,
which used to be difficult to attain simultaneously.
The present invention has been accomplished on the basis of the
above-mentioned discoveries and provides a water and oil repellant
having desoiling properties composed of a polyfluorinated
group-containing copolymer obtained by copolymerizing the following
monomers a and b as essential constituting components:
a: a polyfluorinated group-containing monomer
b: an amphipathic monomer having a hydrophilic moiety and a
lipophilic moiety.
Now, the present invention will be described in detail with
reference to the preferred embodiments.
In the novel water and oil repellant of the present invention, it
is preferred that the weight ratio of a/b in the polyfluorinated
group-containing copolymer is 65-95/5-35, and the total content of
a and b in the copoiymer is at least 80% by weight.
In the present invention, the polyfluorinated group-containing
monomer may be an acrylate or methacrylate containing a terminal
perfluoroalkyl group having from 3 to 20 carbon atoms, preferably
from 6 to 14 carbon atoms, such as
A fluoroalkyl group-containing polymerizable compound such as
H(CF.sub.2).sub.10 CH.sub.2 OCOCH.dbd.CH.sub.2 or CF.sub.2
Cl(CF.sub.2).sub.10 OCOCH.dbd.CH.sub.2 may also be mentioned.
However, the above-mentioned monomer having a terminal
perfluoroalkyl group is preferred from the viewpoint of the water
and oil repellency.
In the present invention, the amphiphatic monomer having a
hydrophilic moiety and a lipophilic moiety is the one having, as
the hydrophilic moiety, a non-ionic group such as a polyoxyethylene
chain, an anionic group such as a sulfonic acid group or a
carboxylic acid group, or a cationic group such as an ammonium salt
or an amine salt, and, as the lipophilic moiety, a polyoxypropylene
chain, a polyoxybutylene chain or an alkylene chain. Usually, an
amphipathic monomer having a hydrophilic-lipophilic balance (HLB)
of hydrophilic moiety/lipophilic moiety being from 5 to 15 is
selected. In the present invention, it is particularly preferred to
employ a mixed polyoxyalkylene chain-containing amphiphatic monomer
which has, as the hydrophilic moiety, a polyoxyethylene chain and,
as the lipophilic moiety, a polyoxypropylene chain capable of
controlling the crystallinity of the polyoxyethylene chain. Namely,
such a mixed polyoxyalkylene chain-containing amphipathic monomer
is advantageous from the viewpoint of the reactivity for the
copolymerization with the polyfluorinated group-containing monomer
and the availability. It is also excellent in providing high
performance of the SR properties and the water and oil repellency
simultaneously. Particularly preferred as such an amphipathic
monomer is an acrylate or methacrylate of the formula:
wherein R.sup.1 is H or CH.sub.3, R.sup.2 is H or a C.sub.1
-C.sub.20 alkyl or aralkyl group, m.gtoreq.1, n.gtoreq.1, and
60.gtoreq.m+n.gtoreq.2.
In the present invention, the amphiphatic acrylate or methacrylate
having the above formula is preferably selected from those having a
polyoxyalkylene chain moiety with HLB of from 5 to 15. It is usual
to employ the one wherein m+n=5 to 30, and m/n=1/4 to 4/1,
preferably 1/2 to 2/1. R.sup.1 may be H or CH.sub.3, but R.sup.2 is
preferably a C.sub.1 -C.sub.20 alkyl group rather than H. For
example, R.sup.2 is preferably a methyl group or a C.sub.2
-C.sub.18 alkyl group.
In the specified copolymer of the present invention, the weight
ratio of the polyfluorinated group-containing monomer (component
a)/the specified amphipathic monomer component b) is usually from
65-95/5-35, preferably 70-90/10-30, and the total content of
components a and b in the copolyer is usually at least 80% by
weight, preferably at least 85% by weight.
In the present invention, in addition to the above-mentioned
essential components a and b, one or more additional monomers such
as a monomer having a cross-linking group or an adsorption group to
fibers, a high Tg monomer for improving the film-forming property,
or a low Tg monomer for improving the flexibility of the coating
film, may be incorporated without any particular restriction.
To obtain the copolymer of the present invention, various systems
and conditions for the polymerization reaction may be employed, and
any of various polymerization systems such as bulk polymerization,
solution polymerization, suspension polymerization, emulsion
polymerization, radiation polymerization and photo polymerization
may be employed. As the polymerization initiating source, various
polymerization initiators such as an organic peroxide, an azo
compound and a persulfate as well as ionized radiation such as
.gamma.-rays, may be employed. As an emulsifier for emulsion
polymerization, almost all emulsifiers including anionic, cationic
and non-ionic emulsifiers may be used. Thus, it is possible that
the polymerizable compound as the starting material is dissolved in
an organic solvent and polymerized by solution polymerization by
the action of a polymerization initiating source (such as a
peroxide or azo compound soluble in the organic solvent used, or
ionized radiation). The solvent suitable for the solution
polymerization includes trichlorotrifluoroethane,
tetrafluorodifluoroethane, methylchloroform, ethanol, isopropanol
and a solvent mixture thereof.
With respect to the composition of the organic solution thus
obtained, there is no particular restriction as to the
concentration of the specified copolymer in the organic solvent.
Usually, however, satisfactory properties can be imparted in the
treatment of fiber fabrics if the concentration is at least about
0.05% by weight. Further, it is possible to prepare the composition
in the form of a concentrated solution having a concentration of
from 4 to 50% by weight, preferably from 6 to 35% by weight, so
that it will be diluted for use to a concentration of from 0.05 to
4% by weight, preferably from 0.3 to 1.5% by weight. Thus, the
concentration of the specified copolymer can be adjusted within a
wide range of from 0.05 to 50% by weight, preferably from 0.3 to
35% by weight. If the concentration is too low, the effect for
imparting the desired properties will be inadequate, and if the
concentration is too high, it will be difficult to obtain a uniform
solution.
Further, in the present invention, it is possible that the organic
solution is prepared as described above, then a propellant such as
dichlorofluoromethane, monofluorotrichlorom-ethane,
dichlorotetrafluoroethane, propane, butane, vinyl chloride,
dimethyl ether, CO.sub.2 or N.sub.2 O is added thereto, and the
mixture is filled in a container to obtain an aerosol.
The feature of the present invention is significant particularly in
the polymerization in an aqueous dispersion system. Namely, the
copolymerization system of the present invention may be a solution
polymerization system as described above in which a high
performance can of course be obtained. However, according to the
present invention, the water and oil repellency and the SR
properties can be attained simultaneously even in the aqueous
dispersion system, in which the conventional SR type water and oil
repellant can hardly attain the desired properties. It presents a
significant advantage in the industrial operation that high
performance can be obtained by an aqueous dispersion system. For
example, with such a system, the flash point is high as compared
with the organic solvent system, or no flash point exists, the
composition of the treating bath can easily be controlled, and no
adverse effects will be imparted to the articles to be treated.
Usually, the water and oil repellant of the present invention may
be prepared in the form of a concentrated aqueous dispersion having
a solid concentration of from 5 to 50% by weight, preferably from
15 to 30% by weight, so that it may be diluted at the time of
treatment to a concentration of from 0.1 to 5.0% by weight.,
preferably from 0.3 to 2.0% by weight.
The water and oil repellant of the present invention may be applied
to the articles to be treated by an optional method depending upon
the type of the articles to be treated or the above-mentioned
preparation system (e.g. the aqueous dispersion, the solution or
the aerosol). For example, in the case of the solution system, it
is possible to employ a method wherein the repellant is deposited
on the surface of the articles to be treated by a known coating
method such as a dip coating method, followed by drying. If
necessary, the repellant is applied together with a suitable
cross-linking agent, followed by curing. In the case of the aerosol
system, the repellant can simply be sprayed to the articles to be
treated, whereupon it is immediately dried to provide adequate
properties. In the case of the aqueous dispersion system
particularly suitable in the present invention, the articles to be
treated are dipped in a treating bath prepared to have the
above-mentioned solid concentration, then squeezed to a suitable
extent so that the latex is deposited on the surface, followed by
drying and curing. Also in this case, a cross-linking agent may be
incorporated, if necessary.
Further, to the polyfluorinated group-containing specified
copolymer, other polymer blenders may be incorporated. Further,
other water repellants or oil repellants, or optional additives
such as insecticides, flame retardants, antistatic agents,
dyestuffs, stabilizers or crease preventing agents, may be
incorporated, as the case requires.
The articles to be treated by the water and oil repellant of the
present invention are not restricted to fiber fabrics, and various
examples may be mentioned, including glass, paper, wood, leather,
fur, asbestos, bricks, cement, metals and their oxide, porcelains,
plastics, coated surfaces and plasters. As the fibrous fabrics,
fabrics made of animal or plant natural fibers such as cotton, wool
or silk; various synthetic fibers such as polyamide, polyester,
polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride or
polypropylene; semisynthetic fibers such as rayon or acetate;
inorganic fibers such as glass fiber or asbestos fiber; or blends
of these fibers, may be mentioned.
In the present invention, the water and oil repellant is believed
to provide high water repellency under a normal condition since the
polyfluorinated groups such as perfluoroalkyl groups cover the
surface of the cloth. At the time of washing, however, the
hydrophilic moiety contained in the copolymer appears on the
surface of the cloth to provide wettability to a soap solution and
thereby to improve the desoiling properties. This is believed to be
the reason why the water repellency and desoiling properties can be
obtained simultaneously. Further, the amphiphatic monomer exhibits
a suitable lipophilic prpperties during the polymerization,
especially during the polymerization in an aqueous dispersion
system (such as suspension polymerization or emulsion
polymerization), whereby the distribution to the aqueous phase is
controlled, and the compatibility with the polyfluorinated
group-containing monomer is improved. Consequently, the random
copolymerization proceeds smoothly, and the water and oil
repellency and the desoiling properties are believed to be thus
obtainable simultaneously and advantageously.
However, it should be understood that the above explanation is
intended solely to help understand the present invention and by no
means restricts the present invention.
Now, the present invention will be described in further detail with
reference to Examples. However, it should be understood that the
present inventioniis by no means restricted by these specific
Examples.
In the following Examples, the water repellency and the oil
repellency are represented by the following standards.
Namely, the water repellency is represented by the water repellency
number (see the following Table 1) by the spray method of JIS
L-1005. The oil repellency was determined by placing a few drops (a
diameter of about 4 mm) of the test solution as shown in the
following Table 2, on a sample cloth at two locations, and
evaluating the infiltration condition upon expiration of 30
seconds. (AATCC-TM 118-1966).
TABLE 1 ______________________________________ Water repellency No.
State ______________________________________ 100 No wetting was
observed on the surface. 90 The surface was slightly wetted. 80 The
surface was partly soaked. 70 The surface was soaked. 50 The entire
surface was soaked. 0 The entire cloth was completely soaked.
______________________________________
TABLE 2 ______________________________________ Oil Surface tension
repellency Test solution dyne/cm, 25.degree. C.
______________________________________ 8 n-Heptane 20.0 7 n-Octane
21.8 6 n-Decane 23.5 5 n-Dodecane 25.0 4 n-Tetradecane 26.7 3
n-Hexadecane 27.3 2 Hexadecane 35/Nujol 65 29.6 mixed solution 1
Nujol 31.2 0 Poorer than 1 --
______________________________________
The tests for desoiling properties (SR properties) were conducted
as follows. A sample cloth was placed on a blotting paper spread
horizontally, five drops of heavy oil-B were dropped thereon, a
polyethylene sheet was placed thereon, and a weight of 2 kg was
loaded thereon. 60 minutes later, the weight and polyethylene sheet
were removed, the excess oil was wiped off, and the sample cloth
was left to stand at room temperature for one hour. Then, the
sample cloth and ballast cloth were charged into an electric
washing machine with a capacity of 35 liters in a total amount of 1
kg, washed at 40.degree. C. for 10 minutes by using 60 g of a
detergent (Super Zab, trade name), rinsed and dried in air. The
stained level of the sample cloth was compared with the
photographic standards of AATCC Test Method 130-1970 and the
desoiling properties of the sample cloth were represented by the
corresponding standard level.
TABLE 3 ______________________________________ Desoiling levels
Evaluation standards ______________________________________ 1
Remarkable stains were observed. 2 Substantial stains were
observed. 3 Slight stains were observed. 4 No substantial stains
were observed. 5 No stain was observed.
______________________________________
The water repellency number, the oil repellency and the SR
properties marked with symbol + indicate that the respective
properties are slightly better.
EXAMPLE 1
Into a glass ampoule having an internal capacity of 100 ml, 8.0 g
of CH.sub.2 .dbd.CHCOOC.sub.2 H.sub.4 C.sub.x F.sub.2x+1 wherein x
is from 6 to 16 and an average of 9 (hereinafter referred to simply
as FA), 2.0 g of ##STR1## (hereinafter referred to simply as POEP),
20 g of trichlorotrifluoroethane 0.2 g of azobisisobutyronitrile
and 0.05 g of-t-dodecylmercaptan were charged. The gas phase of the
ampoule was replaced by nitrogen, and the ampoule was closed,
heated and shaked at 60.degree. C. for 12 hours for
copolymerization. The copolymer solution thus obtained was diluted
with trichlorotrifluoroethane to obtain a solution having a solid
content of 0.6% by weight. To this diluted solution, a polyester
cloth was dipped, then dried in air and subjected to heat treatment
at 150.degree. C. for 3 minutes. The water repellency (WR), the oil
repellency (OR) and the SR properties of the treated cloth were
measured. The results are shown in Table 4.
COMPARATIVE EXAMPLE 1
In the same manner as in Example 1, the copolymerization, the
preparation of the solution, the treatment and the measurement of
the properties were conducted except that instead of POEP in
Example 1, CH.sub.2 .dbd.C(CH.sub.3)COO(C.sub.2 H.sub.4
O)--CH.sub.3 (hereinafter referred to simply as M90G) was used. The
results are shown in Table 4.
EXAMPLE 2 and COMPARATIVE EXAMPLE 2
In the same manner as in Example 1, the copolymerization, the
preparation of a solution, the treatment and the measurement of the
properties were conducted except that the monomer as identified in
Table 4 was used. The results are shown in Table 4.
TABLE 4 ______________________________________ Copolymer After
washing composition Initial 5 times (wt %) OR/WR SR OR/WR SR
______________________________________ Example 1 FA/POEP=80/20
6/100 4 6/70.sup.+ 3 Example 2 FA/PMEP=80/20 6/100 4 6/70.sup.+ 3
Compara- FA/M90G=80/20 6/70 4 5/50.sup.+ 3 tive Example 1 Compara-
FA/PE350=80/20 6/60 2 5/50.sup.+ 1 tive Example 2
______________________________________ Note: The SR properties were
measured after the sample was left to stand for on hour.
In Table 4, PMEP represents ##STR2##
EXAMPLE 3
A monomer/emulsifier/water mixture comprising 32.0 g of FA, 10.0 g
of POEP, 1.5 g of polyoxyethyleneoleyl ether, 0.25 g of
trimethylstearylammonium chloride, 10.0 g of ethyl acetate and
121.3 g of deionized water, was emulsified by a high pressure
homogenizer. Then, 50 g of the emulsion thus obtained, 0.24 g of
azobisisobutyronitrile and 0.12 g of tert-dodecylmercaptan were
charged into a 100 ml glass ampoule. The gas phase was replaced by
nitrogen, and the mixture was copolymerized-:t 60.degree. C. for 12
hours. The emulsion thereby obtained was diluted with deionized
water to obtain a treating bath having a solid content of 1.0% by
weight. A polyester cloth was dipped therein, then squeezed by an
angle to a pick up of 70% and then dried by hot air at 130.degree.
C. for 3 minutes and cured at 170.degree. C. for one minute. The
WR, OR and SR properties of the treated cloth are shown in Table
5.
EXAMPLES 4 to 7 and COMPARATIVE EXAMPLES 3 to 4
The copolymerization, the preparation of a treating bath and the
treatment were conducted in the same manner as in Example 3 except
that the monomer composition in Example 3 was changed to the
monomers and the amounts as identified in Table 5. The results are
shown in Table 5.
TABLE 5 ______________________________________ Copolymer After
washing composition Initial 5 times (wt %) OR/WR SR OR/WR SR
______________________________________ Example 3 FA/POEP=80/20 6/90
4 5/70 3 Example 4 FA/PMEP=80/20 6/90 4 5/70 3 Example 5
FA/POEP/PP800 6/90 4 5/80 3-4 = 70/20/10 Example 6 FA/PCPE/PP800
7.sup.- /90.sup.+ 4-3 5/80 3 = 70/20/10 Example 7 FA/PMEP/PP800 =
70/20/10 6/90 4 5/80 3-4 Compara- FA/M90G=80/20 6/70 3 5/50 2 tive
Example 1 Compara- FA/M90G/PP800 6/70 3 5/60.sup.- 2 tive =
70/20/10 Example 2 ______________________________________ Note: The
SR properties were measured after the sample was left to stand for
on hour.
In Table 5, PP800 represents ##STR3##
The water and oil repellant of the present invention has an
excellent effect of providing the water and oil repellency and the
desoiling properties simultaneously, and it also exhibits an effect
such that after the washing operation, a high level of water and
oil repellency can be obtained without heat treatment.
Particularly, it provides remarkable effect such that a high level
of both properties can be obtained in an aqueous dispersion
system.
* * * * *